Pull up resistor

Discussion in 'General Electronics Chat' started by Marc0, Sep 1, 2012.

  1. Marc0

    Thread Starter Member

    Nov 28, 2011
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    Hi, can someone please explain me in simple words how a "pull up resistor" works?
     
  2. Jony130

    AAC Fanatic!

    Feb 17, 2009
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    nobody0608, #12, anhnha and 1 other person like this.
  3. Marc0

    Thread Starter Member

    Nov 28, 2011
    42
    1
    Haha that was awesome...thank you!
     
  4. Jony130

    AAC Fanatic!

    Feb 17, 2009
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    This also refers to "pull down" resistor. And sometimes we use pull up/pull down resistor in analog circuit as well.
     
  5. Marc0

    Thread Starter Member

    Nov 28, 2011
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    Good to know. I was messing with a computer PSU, and the power on mechanism works just like this, there's no switch but a motherboard that "speaks" only logic states (0 or +5). The PSU green wire is pulled up by the PSU itself (+5) and must be lowered to 0 to turn the PSU fully on.
    Because there is no motherboard here, I just use a jumper to connect the green wire to one of the available PSU grounds.
     
  6. #12

    Expert

    Nov 30, 2010
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    Too cute! LOL!
     
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